[PATCH 2/2] soc: xilinx: Fix event manager CPU hotplug state cleanup

[Prasanna Kumar T S M]

On driver removal, the event manager removes the CPUHP_AP_ONLINE_DYN
CPU hotplug state instead of the its actual state. This can leave the
event manager callbacks dangling. Use the actual CPU hotplug state
during driver removal.

Hotplug registration failures are also ignored, allowing probe to
succeed without the callbacks needed to enable event interrupts on
CPUs brought online later.

Fixes: c7fdb2404f66 ("drivers: soc: xilinx: add xilinx event management driver")
Signed-off-by: Prasanna Kumar T S M <ptsm at linux.microsoft.com>
---
 drivers/soc/xilinx/xlnx_event_manager.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/soc/xilinx/xlnx_event_manager.c b/drivers/soc/xilinx/xlnx_event_manager.c
index f733dc42b3b1..2d8bfeab4190 100644
--- a/drivers/soc/xilinx/xlnx_event_manager.c
+++ b/drivers/soc/xilinx/xlnx_event_manager.c
@@ -24,6 +24,7 @@ static DEFINE_PER_CPU_READ_MOSTLY(int, dummy_cpu_number);
 
 static int virq_sgi;
 static int event_manager_availability = -EACCES;
+static enum cpuhp_state hp_state;
 
 /* SGI number used for Event management driver */
 #define XLNX_EVENT_SGI_NUM	(15)
@@ -625,8 +626,6 @@ static int xlnx_event_init_sgi(struct platform_device *pdev)
 
 static void xlnx_event_cleanup_sgi(struct platform_device *pdev)
 {
-	cpuhp_remove_state(CPUHP_AP_ONLINE_DYN);
-
 	on_each_cpu(xlnx_disable_percpu_irq, NULL, 1);
 
 	irq_clear_status_flags(virq_sgi, IRQ_PER_CPU);
@@ -660,8 +659,13 @@ static int xlnx_event_manager_probe(struct platform_device *pdev)
 	}
 
 	/* Setup function for the CPU hot-plug cases */
-	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "soc/event:starting",
-			  xlnx_event_cpuhp_start, xlnx_event_cpuhp_down);
+	hp_state = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+			"soc/event:starting", xlnx_event_cpuhp_start,
+			xlnx_event_cpuhp_down);
+	if (hp_state < 0) {
+		xlnx_event_cleanup_sgi(pdev);
+		return hp_state;
+	}
 
 	ret = zynqmp_pm_register_sgi(sgi_num, 0);
 	if (ret) {
@@ -670,6 +674,7 @@ static int xlnx_event_manager_probe(struct platform_device *pdev)
 		else
 			dev_err(&pdev->dev, "SGI %d registration failed, err %d\n", sgi_num, ret);
 
+		cpuhp_remove_state(hp_state);
 		xlnx_event_cleanup_sgi(pdev);
 		return ret;
 	}
@@ -704,6 +709,7 @@ static void xlnx_event_manager_remove(struct platform_device *pdev)
 	if (ret)
 		dev_err(&pdev->dev, "SGI unregistration over TF-A failed with %d\n", ret);
 
+	cpuhp_remove_state(hp_state);
 	xlnx_event_cleanup_sgi(pdev);
 
 	event_manager_availability = -EACCES;
-- 
2.49.0